Graphics processor hardware support for pixel synchronization has enabled a new class of graphics processor algorithms that can employ custom per-pixel computation that is dependent on being executed in precise triangle input order. Adaptive Volumetric Shadow Maps (AVSM) and Order Independent Transparency (OIT) are examples of features that can make use of pixel synchronization. For example, AVSM can be used to provide shadowing and self-shadowing effects for dynamic volumetric media such as hair and smoke. Pixel synchronization support enables the implementation of a raster order view (ROV) version of the AVSM algorithm that is practical for real time use in graphically intensive applications.
However, the ROV-enabled AVSM algorithm has a high memory bandwidth and computation cost. The entire per-pixel data set is loaded, decoded, compressed, encoded and stored for each new node (e.g., partial occluder) insertion. Representative workloads may use more than 100 insertions per texture element, per frame. Such overhead can have the result of limiting the visual quality level that is possible at an acceptable graphic processor execution cost.